What does a kilo of home-grown oyster mushrooms really cost? An honest calculation
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Growing your own is much cheaper, surely? We get that question a lot, and the honest answer is: it depends. On the method, on your patience and on what you count. Below we work through three ways of growing oyster mushrooms, with round figures roughly as they stand in the summer of 2024. Prices change, the proportions do not.
What are we comparing against?
Oyster mushrooms in the supermarket or at the market cost somewhere between ten and fifteen euros per kilo depending on season and packaging. Organic or unusual varieties such as pink and golden oyster sit well above that, or simply cannot be bought. That is the bar.
Method 1: the grow kit
An XL grow kit of just over three kilos of substrate costs around twenty euros. In normal use it yields about a kilo of oyster mushrooms, spread over two to four flushes; with good care and a patient third flush sometimes more. So expect fifteen to twenty euros per kilo. That is roughly shop price, so no saving. What you do buy: mushrooms fresher than anything in the shop, the experience of growing, and the certainty that it works. For a first time that is a fine trade. As a cost saving, the grow kit was never meant to be one.
Method 2: spawn and a bucket of straw
An 80 gram pouch of spawn costs under ten euros and is enough for a bucket of ten to twenty litres. Straw costs next to nothing (a bale from a farmer or pet shop is a few euros and lasts months), you have or find the bucket, and pasteurising happens in a pan or drum of hot water. A successful bucket yields one and a half to two and a half kilos. That brings the price to four to six euros per kilo, less than half of shop price. The catch: if the bucket fails through contamination, the sums change in one go. The first bucket fails beginners more often than the fifth. Average a few attempts over a year and the figure stays well below shop price.
Method 3: the log
Twenty-five plugs cost around eleven euros, wax included. The log is free if you know where to look. Nothing comes out in the first year, and that is where most people abandon the calculation. From the second year a one-metre log gives two to three flushes a year of a few hundred grams to a kilo each, for three to five years. Over the life of the log you get several kilos for eleven euros, in other words two to four euros per kilo, and heading towards zero after that. There is no cheaper way to eat mushrooms than a log you inoculated in 2024 and are still harvesting in 2027.
| Method | Investment | Yield | Price per kilo | Waiting time |
|---|---|---|---|---|
| XL grow kit | approx. 20 euros | approx. 1 kilo | 15 to 20 euros | 1 to 2 weeks |
| Spawn + bucket of straw | approx. 10 euros | 1.5 to 2.5 kilos | 4 to 6 euros | 4 to 8 weeks |
| 25 plugs + log | approx. 11 euros | several kilos over years | 2 to 4 euros, falling | 6 to 18 months |
What is not counted here?
Your time. A grow kit takes five minutes of misting a day, a bucket an afternoon of preparation, a log a morning of drilling. Count your hours and all three end up above shop price, just like growing tomatoes or baking bread. But if you count your hours, you also have to count that it is fun. So we do not, and you probably do not either.
The honest conclusion
If you want to eat cheaper than the supermarket, choose spawn or plugs and accept that it takes longer and sometimes fails. If you mainly want certainty and mushrooms on your plate within two weeks, choose the grow kit and treat the price as tuition. And anyone who does both, in the order we recommended in an earlier piece, will be eating oyster mushrooms a year from now for a fraction of shop price without it ever having felt like economising.